Relay.



C. E. HARTHAN.

RELAY.

APPLICATION FILED MAY19.19I5.

lm/entor; Charles Bl-|art han His Attorney.

HAR E -JAN, 01 LYNN, MASSACHUSETTS, 36R Ti) GENEEAL ELEG' 'C @QMEMTY, .'l. GQBPUEATIQIQ 9L 03K.

.i. do...

mum

specification of Letters Patent.

Patented New 28, 11916,

- Application filed 19, Serial Pic. eases- Lynn, in the county of Essex, State of Massachiisetts, have invented certain new and useful Improvements in Relays, of which the following is a specificatio lily present invention relates to electro, magnets and more particularly to electromagnets of the class commonly known as relays which are employed for opening closing electrical circuits.

@ne of the obiects of my invention is to provide an eiiicient and reliable construction for an electromagnet of this type.

A i lore specific object of my invention is to provide a satisfactory reverse current re y use with an automobile starting s teni in which a small direct current dynamo electric machine is supplied with current from a storage battery and runs as a motor to sta t the engine of the automobile. After the engine has attained its normal speed the dynamo electric machine may he drives by engine andrun as a generator to charge the storage battery. In systems of this description it is desirable that the generator should be connected to the battery only when its voltage exceeds that of the battery. The function of my relay in this particular instance is to connect the generator to the battery as soon as it reaches a certain predetermined voltage and to cause it to be disconnected. therefrom as soon as its voltage falls below that of the battery.

The features oi my invention which I consider novel are pointed out with particularity in the appended claims.

The invention itself, however, with further objects and advantages will best be understood by reference to the following de scription taken in connection with the accompanying drawing in which- Figure 1 shows a cross sectional view of a relay constructed in accordance with my invention; Fig. 2 is a perspective View of the same; and Fig. 3 illustrates diagrammatically the electrical connections which may be employed with my relay in an autorac bile starting system. i

As indicated" in the drawing the magnet comprises series winding 1 of heavy wire having a small number of turns and shiuit winding 2 of finer wire haying a l number of turns. The spoolen-wlu'ch these windings are placed consists'of a etic core 3 with a non-magnetic end member 4-, and a second end member 5 which may be of magnetic or hon-magnetic material as desired. Theusual insulating members 6 are employed between the windings and between the windings aed the spool. lhe electromagnet is surrounded on three sides by a shaped yol Ie '2 of magnetic material which provides a path of low reluctance for the flux set up by current in the windings. A movable armature 8 of magnetic material is mounted. on the contact member 9 which is pivoted at 10 one arm of the magnetic yoke. A second contact'niember 11 is rigidly ecured to, but insulated from, the othe arm or" the yoke. Those contact members and the member 12 which secures the contact member 9 to the magnetic yoke are all preferably of non-magnetic -material. A flat spring 13 oi non-magnetic material fastened to the armature 8 normally holds the ture away from the magnet and keeps the two contact members separated at 14-, This spring bears upon the end of the magnetic yoke at 15 and thus serves as a non-reagnetic spacer between the armature and the yoke, thereby preventing freezing of the armature when it is attracted by the magnet. A stop 16 which may be adjustable, if desired, normally holds the contact member 9 and armature 8 in a position where the armature will beattracted as soon as the magnet exerts a predetermined pull on the armature. It will be noted that with the construction which I have described and illustrated the magnetic circuit which comprises the yoke 7 and the armature 8 has a small air gap at the point 15 and that the point 14 at which the contact members separate to open the circuit is adjacent this air Asa result the stray magnetic field across the air gap acts on any are which I. may form when the circuit is opened and as.-

sistsin extinguishing'the same.

be soldered A flexible co nector 17 may to member 12 and contact member 9 to pro- 'vide goodelectrical conductivity betweenthis contact member and the frame work of 1' the magnet. One terminal of the series coil 10, indicated. One terminalof the shunt wind ing isalso connected to the framework ofis connected to contact member ll at 18 as the magnet at'19 as shownin Fig '3. Contacts 20 of silver or other suitable metal.

may be provided on the ends of the. contact members 9 and 11.

Having described the principal structural features of my invention 1 will now explain the magnet by conductor 22 while: the otherits operation when employed in an automobile starting system as indicated in Fig. 8.

Oneterminal of the dynamo electric, ma-

chine 21 is connected to the framework of terminal of the machine is connected by conductor 23 to the shunt winding ot the.

magnet, thereby providing a permanently closed circuit from'machine 21 through the shunt winding. When it is desired to start the engine of the automobile switch 24 is closed thereby connecting battery 25 to the machine 21 which then runs as a motor and starts the engine. as soon as the engine begins to run by its own power switch 24 is opened. it it is desired that the battery be charged the connection between the engine and the dynamo electric machine is retained whereby the latter becomes a generator. As

soon as its voltage has reached a predeten mined value the shunt winding'2 produces a suilicient pullin'the magnet toattract the armature 8 and close the contacts at '14:. This connects the battery to the generator through the series winding and as long as thebattery is being charged the current.

through the series winding assists the shunt current in attracting the armature 8. as

soon, however, as the voltage of battery 25 exceeds that of generator.2l-"current starts to flow in thereverse direction and the magnetization produced by the series winding opposes'that produced by the shunt winding allowing the spring 13 to retract armature 8 and open the battery circuit.

While I have illustrated the application of my invention to an'automobile starting system, it will be evident that it may equally well be used for other purposes and '1 do not wish to be limited to this particular ap; plication. It will also be apparent that many modifications may be made inthe structural details of my device without departing from the scope of my invention.

What I claim asnew and desire to secure by Letters Patent of the United States, is

said yoke for normally holdi v above said air i a 5. The combination in an electromagnet of a magnetizing winding, a U-shaped magv incense 1. The combination in an electromagnet of a core of magnetic material, windings surrounding said core, aU-shaped'magnetm yoke surrounding three sides of said windings, a pivoted contact membencarried-by one arm of said magnetic yoke, an armature carried by, said contact member so as to be attracted by the magnetic core and yokewhen current flows through saidw'indings and a spring for normally holding said armature in,a retracted position and so posi tioned that it isfinterposed between the. armature and the yoke when the armatureis" attracted.

' 2.,ihe combinatlon in an electromagnet of a coreot magnetic material, windings when attracted thereby.

' 3. The combination in an electromagnet of a magnetizing coil, a magnetic circuit of I low reluctance surrounding said coil, havng an air gap therein and contacts ada ted- .to be made and broken by the action 0 the electromagnet, located adjacent to and above said air'gap.

- e. The combination an electromagnet of a magnetizing winding, a magnetic yoke surrounding. said winding on three sides, a

movable armature of magnetic material ad'- jacent the fourth side of said winding and forming a part of the magnetic circuit, an air gap in the magnetic circuit between said armature and said yoke and contacts, adapted to be made and broken by the movement of said armature located adjacent to and gap.

netic yoke surrounding said winding on three sides, a fixed contact carried by one arm of said yoke, a coiiperating movable yoke, an armatureso arranged as to be attractedby the'magnetic yoke when the latter is magnetized and an air gap in the magnetic circuit between said armature and the end of said yoke, said air gap being located adjacent said contacts.

'6. The combination in an electromagnet of a magnetizing winding, a- U-shaped magnetic yoke surrounding said winding on three sides, a fixed contact carried by one surrounding-said core, a U-shaped'magnetic yoke surrounding three sides of said wind- "contact carried by the other armof the and an air gap in the magnetic'circuit be tween said armature and the end of said yoke, said air gap being located adjacent said contacts.

In Witness whereof, I have hereunto set my hand this 15th day of May, 1915.

CHARLES E. HARTHAN. 

